One of the first parts I’m going to attempt has a bit of a tricky corner situation to it. I’m going to use the female mold out of fiberglass method, but I’m worried about how well I will be able to lay the carbon into the mold.
A couple of spots on the bottom will have two corners which will be like laying carbon into two corners of a box. Any tips/tricks on how to deal with this?
It would be on the bottom of the piece, so I guess I could just fold the part that no one will see. What say you?
I’ll try and dig up a picture of the piece I’m talking about.
You can probably lay the face of the cover part with no problem, so start in the middle of the part/mold laying the carbon fiber. Once you get out to the edges the fabric will want to pleat in probably 6 or more areas. Snip just those areas with scissors so they can overlap and lay down to the mold. If you make clean sharp cuts on the cloth it won’t be too noticeable.
Make sure your resin is:
1: able to stand the temps of the clutch oil (unless it’s a dry clutch?)
2: will not deteriorate in the oil bath!! I’m sure there are some resins that do not like chemicals that might be in motor oil!!
3: Make sure that whatever the pressure is inside the clutch system (again, oil), the cover is strong enough!
4: to answer your question. MAKE A FILLET!! Do not expect any composite fabric to take a sharp 90deg. corner. Well designed molds always take this into account. I think a 1/4" radius would work well depending on your fabric?
Riff, Thanks for the comments, but I’m reffering to the plastic piece that covers the airbox just behind the carberatours. I’m not too keen on making actual engine covers out of CF at the moment.
I would like a little more explanation on point #4, however. Fillet as in “fill-ay”? How would this look if I were laying it into the mold?
EDIT: Sorry, the cover I’m talking about isn’t bronze as I first indicated. It’s more of a dull metallic grey. I’ll try and snap some pics soon.
I was thinking of just folding it from behind to fit it into those corners. you would be able to see it on the back of the piece, but it would just appear as a “seam” on the bottom two corners of the piece which are well out of sight.
getting the material in well is one thing, but more importantly are the steps of all your vacuum materials and your bagging techiniques! make sure all your bagging materials will not bridge and have relief cuts where needed. when it comes time to bagging, make sure you do not go full vacuum until your 100% sure you have no bridging. best thing to do is purposly leave a hole or two open in your bag pleats. Use a rubber squeegie to work your bag in tight corners and slowly increase your bag pressure by closing holes.
oh. THAT bronze piece
1: yeah, you might be able to get the first piece in. Maybe seam the corners, and then when laying up the next few layers, overlap the seams with larger pieces of fabric (ie: don’t cut and dart seams in the same location on each layer, or there will be no strength on the seams, and will crack) That airbox thing looks like the radius is good.
2: fillet as in a inside corner, that is rounded. Think of a caulking a tub, or sink backsplash. It creates a rounded inside corner.
when laying in the fabric, and finally vacuumbagging it, pull a partial vacuum, and make sure you wiggle the fabric in the corners. Pull a vacuum, and release it. Pull it again, and release it. Do that a few times while wiggleing your fingers in the corner, to make sure it’s in there. The pulling of vacuum, and releasing it, makes the fabric nest into the corners better, and even from one layer to the next.
…and if you are going to make more of them, make a silicone back up wedgie (laid on the peel ply) to help force the CF into the corners with the vacuum bagging.
ah, never thought about that!
yeah, adding a shaped object on the outside of the plys will help force the material in. I’d used tackytape wrapped in release film MANY times for a tight cornered part.
I was hoping to make some of these and sell them, but then this guy on the ZRX forums pops up every now and agian with some Japanese hookups, and this just happened to get listed along with every other piece I was thinking of making for some pretty sweet prices. Sucks for me, but I think I still have something to offer.
It looks as if they made the piece more shallow in some areas to reduce the ammount of pleating around the edges. I’ll have to pull my stock one and take some pictures for you all to see. I’ve got to get to something under my tank anway this weekend, so it’ll be a good time to check it out.
i would suggest you make a thin paper template (or cloth, like cotton cloth) of the shape that will conform best inside. this will help for a cleaner job, and not snipping at the carbon while you’re over the mold and tiny carbon hair falls in the mold…
personally, the way i would do it: make the template, then using spray adhesive, stick 2 carbon fabrics one on top of the other at 45 degree angle. this will stop the fabric from fraying when you cut off the template. with a light mist of spray ahdesive in the mold, stick the fabric inside, and make sure it’s tucked in all the corners. then , add some more layers of fabric to reinforce the corners which have no material…then, infuse, or wet layup,or bag it…
